• Journal of Audiology & Otology
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• v.23 no.2
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• pp.69-75
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• 2019

Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

• Korean Journal of Audiology
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• v.23 no.2
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• pp.69-75
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• 2019

Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.215-221
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• 2002

Antioxidants(N-acetyl-1-cysteine, ebselen and glutathione) and growth factors(EGF, PDGF) were studied as a mean of increasing the development of porcine embryos produced by in vitro maturation (IVM) and in vitro fertilization(IVF). Porcine embryos developed to the 2~8 cell stage after IVF were cultured fer 6 to 7 days at 38.5$^{\circ}C$ in NCSU 23 medium containing antioxidants plus growth factors. Cell numbers of blastocysts were counted by fluorescence staining method. The developmental rate beyond morula stages in NCSU 23 containing NAC(1nm) or NAC(1nm) plus EGF(100ng/$m\ell$) or PDGF(5ng/$m\ell$) were 28.1, 32.3 and 35.3%, respectively. NAC plus PDGF group was slightly higher than control group(P>0.05). The developmental capacity in NCSU 23 containing ebselen(10 $\mu$M) or ebselen(10 $\mu$M) plus EGF(100ng/$m\ell$) or PDGF(5ng/$m\ell$) were 17.8, 36.9 and 40.3%, respectively Ebselen plus growth factor groups were significantly higher than control group(P<0.05). The developmental capacity in NCSU 23 containing glutathione(100 $\mu$M) or glutathione(100 $\mu$M) plus EGF (100ng/$m\ell$) or PDGF(5ng/$m\ell$) were 24.1, 30.5 and 27.7%, respectively. There were not difference in all experimental groups(P>0.05). In all experimental groups, there was no significantly differences on the cell number of blastocysts, but ebselen plus growth factor groups were significantly higher than control group. These studies indicate that antioxidants plus growth factors can increase the proportion of embryos that developed beyond morulae stage.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.223-228
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• 2002

This study was carried out to examine the effects of antioxidants and buthionine sulfoximide(BSO) on the development of porcine in vitro maturation(IVM) and in vitro fertilization(IVF) oocytes. Cumulus cell free embryos derived from porcine IVM/IVF oocytes were cultured NCSU23 medium with antioxidants or BSO under an atmosphere of 5% $CO_2$ and 5% $O_2$at 38.5$^{\circ}C$ for 5~6 days. The embryos cultured in medium with BSO showed a significanthy(P<0.05) lower rates(8.4~15.7%) of the development to the morulae and blastocyst stage than control group(35.9%). When the embryos were cultured with NAC, ebselen, glutathione and BSO, the proportions of embryos beyond morulae and blastocysts were significantly(P<0.05) higher in medium with NAC(40.5%), ebselen(44.2%) and glutathione(36.0%) than BSO(10.9%). In conclusions, these results indicate that NAC, ebselen and glutathione as a antioxidants can increase the proportion of embryos that develop beyond morulae stage. BSO, intracellular glutathione inhibitors, is suppressed the development of porcine embryos derived from IVM/IVF.

• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.143-151
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• 2002

The present study was conducted to investigate the effects of antioxidants and growth factors on early development of porcine follicular oocytes fertilized in vitro. The embryos without cumulus cells were transferred into NCSU 23 medium and cultured for 5~6 days. The proportions of embryos developed to morula and blastocyst stages were significantly higher (P＜0.05) in medium with 1.0(21.1%) and 2.0mM(22.3%) NAC than in control (14.7%) and 0.5mM NAC (12.2%). When the embryos were cultured in medium with ebselen, the highest proportion(36.9%) of embryos developed to morula or blastocyst stages was obtained in medium with 10 $\mu$M ebselen. Higher proportions of embryos were developed to rnorula and blastocyst stages during culture with 100$\mu$M than control, 50 and 200$\mu$M glutathione. The EGF and PDGF were evaluated as growth factors supplemented to the culture medium for in vitro development of porcine embryos. The proportions of embryos developed to morular and blastocyst stages were significantly higher (P＜0.05) in medium with 100ng/m1 ECF than control, 10 and 50ng/$m\ell$ EGF. However, the proportions of embryos developed to morular and blastocyst stages were not significantly different among concentrations of PDGF. In conclusions, these results indicate that NAC, ebselen and glutathione or EGF and PDGF can increase the proportion of embryos that develop beyond morula stage.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.161.2-161.2
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• 2001

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.46-46
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• 2002

본 연구는 돼지의 미성숙 난포란을 체외에서 성숙, 수정시킨 후, 생산된 체외수정란을 NCSU 23 체외배양액에 항산화제 (NAC, ebselen 및 glutathione) 와 glutathione 합성억제제인 BSO의 첨가가 돼지 체외 수정란의 체외 발육에 미치는 영향을 검토하였다. Glutathione 합성 억제제인 BSO가 돼지 수정란의 체외 발육에 미치는 영향을 검토한 결과, 0, 1.0 및 5.0mM의 BSO 을 첨가하여 상실배기 이상 발육된 체외 발육 성적은 각각 35.9, 15.7 및 8.4%로서 BSO 첨가구가 대조구에 비해 통계적으로 유의하게 낮은 체외배율성적을 나타냈으며 (P＜0.05), NAC 1.0mM, ebselen 10μM 및 glutathione 100μM 과 BSO 1.0 mM 을 각각 첨가하여 체외 배양을 실시한 경우, 상실배 이상 발육된 체외 발육율은 40.5, 44.2, 36.0 및 10.9%로서 항산화제 첨가구가 BSO 첨가구보다 통계적으로 유의하게 높은 체외 발육 성적을 나타냈다 (P＜0.05). 모든 처리구에서 체외 수정 후 생산된 배반포기 수정란의 세포수에는 차이가 인정되지 않았다. (중략)

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.44-44
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• 2002

본 연구는 돼지의 미성숙 난포란을 체외에서 성숙, 수정시킨 후, 생산된 체외 수정란을 NCSU 23 체외배양액에 항산화제(NAC, ebselen 및 glutathione) 와 성장 인자 (EGF, PDGF)의 첨가가 돼지 체외 수정란의 체외 발육에 미치는 영향을 검토하였다. NAC을 0, 0.5, 1.0 및 2.0 mL 첨가하여 체외배양한 결과, 상실배기 이상 발육된 체외발육성적이 1.0mL과 2.0 mM 첨가구가 여타구보다 유의하게 높은 체외발육성적을 나타냈다.(p〈0.05). (중략)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.304.1-304.1
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• 2002

Brain injury resulting from cerebral ischemia remains a major public health problem. Aloesin. main component of aloe possesses various biological activities such as wound healing, anti-gastric ulcer, and chemopreventive activity. In this study we investigated whether treatment with aloes in could protect brain injury induced by permanent focal cerebral ischemia in rats. We also compared aloes in with other neuroprotective. drugs such as MK801 and ebselen. (omitted)

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1582-1589
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• 2009

Bacterial UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) catalyzes the transfer of enolpyruvate from phosphoenolpyruvate (PEP) to uridine diphospho-N-acetylglucosamine (UNAG), which is the first step of bacterial cell wall synthesis. We identified thimerosal, thiram, and ebselen as effective inhibitors of Haemophilus influenzae MurA by screening a chemical library that consisted of a wide range of bioactive compounds. When MurA was preincubated with these inhibitors, their 50% inhibitory concentrations ($IC_{50}s$) were found to range from 0.1 to $0.7\;{\mu}M$. In particular, thimerosal suppressed the growth of several different Gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhimurium at a concentration range of $1-2\;{\mu}g/ml$. These inhibitors covalently modified the cysteine residue near the active site of MurA. This modification changed the open conformation of MurA to a more closed configuration, which may have prevented the necessary conformational change from occurring during the enzyme reaction.